1. Field of the Invention
This invention relates generally to amusement devices and toy drawing apparatus; and more particularly to an amusement apparatus for drawing a distorted caricature by tracing an original photograph or the like.
2. Prior Art
Many simple devices such as pantographs have been introduced for tracing pictures with an enlargement. (For the sake of simplicity of expression, as used in this document the word "enlargement" is to be understood as encompassing enlargement by a factor less than unity--i.e., reduction.)
In such devices a design objective is generally to provide roughly equal enlargement in all directions. Such an arrangement preserves shapes from the original picture in the tracing.
One prior device, however, did provide selectively different enlargement factors in different directions, thereby introducing distortion into the traced shapes. That device was sold commercially under the trademark "Krazy Kopier" and was essentially a parallelogram pantograph.
The four bars of the parallelogram included one bar that was generally disposed fore-and-aft along the left edge of the apparatus, and that extended rearward beyond the parallelogram to a fixed pivot. The pivot constrained the two parallelogram corners along that left-hand bar to rotate about the fixed pivot.
The first parallelogram corner--that is, the corner closest to the fixed pivot--could do no more than rotate, with a fixed and relatively small radius, about the pivot. The radius to that first corner was roughly half the length of the left-hand bar.
The opposite corner of the parallelogram, by contrast, was essentially free to swing in two dimensions over a very large range of positions. A tracing stylus was mounted to that opposite corner, and used to trace an original picture.
Drawing implements were shiftably mounted along a cross-arm or drawing arm of the parallelogram. That arm was attached to the "first corner" mentioned above, and extended to the right across the apparatus. The cross-arm was thus mounted halfway out the pantograph, along one axis of the system, from the pivot to the stylus.
A drawing implement mounted to the parallelogram at a point halfway from the pivot point to the tracing stylus--along both directions of the pantograph--would produce a drawing very similar in shape to the original traced picture, but about half of the overall size. This was the case for a drawing implement mounted at a point halfway across the cross-arm.
An implement mounted on the cross-arm but nearer to the above-mentioned "first" corner would produce a drawing of nearly the same size in the lateral direction, but much smaller in the fore-to-aft direction. The opposite effect was created by a drawing implement mounted at a "second" corner of the parallelogram, near the right end of the cross-arm: the drawing produced would be nearly the same size in the lateral direction, but much larger fore-to-aft.
Implements at intermediate positions would produce intermediate effects. Thus the "Krazy Kopier" device was capable of a variety of visual effects, but required seven moving parts (four bars, and three sliding pen holders secured along the cross-bar) and five smoothly operating pivots--that is, pivots that operated during making of a tracing, and therefore were required to operate smoothly.
Furthermore, the variety of visual effects was limited in one regard. The "Krazy Kopier" device had a fixed holder for positioning the original picture. This holder included corner slots for retaining the picture.
Children or other users who used the fixed holder were limited to lengthening or foreshortening distortions that were aligned with the fore-to-aft (i.e., top-to-bottom) direction of the picture,. Therefore the prior art did not provide a very economical and simple tracing device, or a tracing device capable of introducing a distortion selectively in any arbitrary orientation relative to the picture.